Also, Domhnall of Zena will sell the armor of Artorias of the Abyss once when you kill him in AotA... And damn that armor is fucking cool. While heavy armor and has not that good physical defense, it has a very decent Fire defense stat and also a bit of both Lightning and Magic.

Also, getting the Abyss Greatsword and the Cleansing Shield makes you look like a damn badass while using that armor.

Well that's why you try to pick targets who aren't looking towards you. It's all a guessing game, really.

Most potential targets are already locked in combat so they'll be shuffling around a lot anyway. Archers move around a lot specifically to counter other archers, and it's just rare to find a normal, running target.